The present invention relates to a motor with a cooling means. More particularly, this invention relates to a motor with a cooling means that can efficiently cool heat of a motor generated during the operation of a motor.
In general, a motor is classified into a DC motor and an AC motor. The DC motor, such as a series motor, a shunt motor and a compound motor, rotates as DC power is supplied to a rotator. The AC motor rotates by using AC power, and an induction motor, a synchronous motor and an alternating current commutator motor are such kinds. Electric energy is consumed in a coil member of a motor and heat is generated while a motor is driven due to a high-speed rotational motion. The generated heat may cause damage to a motor, for example, a severe heat burning of a coil may incur. Therefore, it is necessary that heat generated in the motor while the motor is running must be discharged. Accordingly, there have been many means put forth in effort to resolve the cooling problem in the motor.
FIGS. 1 and 2 illustrate the conventional motor, where FIG. 1 is a perspective view and FIG. 2 is a vertical cross section.
Referring to FIGS. 1 and 2, the conventional motor 100 comprises: a rotation axis 101 located in the center of a motor; a rotator assembly 102 fixed on to the rotation axis 101 by the pressure and rotates with the rotation axis 101; a stator assembly 103 installed in order to surround the rotator assembly 102; a bearing 104 is installed to support the rotation axis 101; and, a stator winding 105 individually placed in upper and lower portions of the stator assembly 103. Also, radial fans 106, 106xe2x80x2 are installed in between upper and lower portion of the bearing 104 and a upper and lower portions of the stator winding 105 to circulate air to cool the inside of the motor. And, outer parts of upper and lower portions of the bearing 104 are attached with an endshield 107 and 107xe2x80x2 consists of a bearing housing 107b, 107xe2x80x2b to protect the interior structure and an air inlet member 107h, 107xe2x80x2h and to draw in the air.
In the conventional motor, when electric power is supplied to the stator winding 105, a rotating magnetic field is generated by the stator winding 105. And, the rotator assembly 102 is rotated through the interaction between the rotating magnetic field and the magnetic field generated by the permanent magnet of the rotator assembly 102. Accordingly, the rotation axis 101 fixed on to the rotator assembly 102 rotates and at the same time the radial fan 106, 106xe2x80x2 fixed on to the rotation axis 101 also rotates.
When the motor is operated for a long period of time, the heat (Joule heat) is generated by the stator winding 105 causing the interior temperature of the motor to rise. The radial fan 106, 106xe2x80x2 rotates along with the rotation axis 101 and the rotator assembly 102, and directs the circulation of an interior air of the motor. As a result of rotation of the radial fan 106, 106xe2x80x2, a heated air existed in between blades of the fans flows to outside by the centrifugal force of the rotation. Accordingly, an interior air pressure of the motor becomes relatively lower than an air pressure of the outside of the motor and the exterior cooler air flows into the interior of the motor through the air inlet 107h, 107xe2x80x2h formed at the horizontal surface of the endshield 107, 107xe2x80x2. Thereafter, the air that induced into the interior of the motor is then drawn out to outside by the fan rotation, thereby the air is continuously circulated. Accordingly, the stator assembly 103 and the rotator assembly 102 are cooled by the air-cooling means to prevent rapid temperature increase in the interior of the motor.
As described above, the conventional motor utilizes the radial fan 106, 106xe2x80x2 as the cooling means. Referring to FIG. 3, the radial fan 106 placed in the upper portion of the rotator assembly 102 has the characteristics of a small air flow and a high static pressure. As a result, amount of air circulated by the radial fan is limited, thus the cooling effect is not efficient. When the motor is rotating at high speed, heat is generated in the upper and lower portions of the bearing 104, however, there is no cooling means to relieve the generated heat. As a result, oil or grease in the bearing 104 becomes dry causing decline in the performance of the bearing and shorten of the bearing life span.
It is a primary object of the present invention to obviate the disadvantages of the foregoing prior art by providing a motor with a cooling means which can more efficiently cool the heat generated in the interior of the motor and the bearing during operation of the motor.
These and other objects are satisfied by a motor with a cooling means comprising: a rotation axis; a rotator assembly fixed to the rotation axis; a stator assembly surrounds the rotator assembly; a bearing attached to both ends of the rotation axis to support the rotation axis; an axial-flow fan used as a cooling means placed between each bearing and the rotator assembly to cool the stator assembly and the rotator assembly; an endshield attached to both ends of a housing to protect the structure and consists a plurality of air intakes; and a plurality of cooling pins formed to the outer surface of endshield to draw out the heat generated in the bearing and the interior of the motor during operation of the motor.
Other objects of the present invention are satisfied by a motor with a cooling means comprising: a rotation axis; a rotator assembly fixed to the rotation axis; a stator assembly surrounds the rotator assembly; a bearing attached to both ends of the rotation axis to support the rotation axis; an axial-flow fan used as a cooling means placed between each bearing and the rotator assembly to cool the stator assembly and the rotator assembly; an endshield attached to both ends of a housing to protect the structure and consists a plurality of air intakes; and a plurality of through holes formed to the rotator assembly to circulate the air.
Other objects of the invention are satisfied by a motor with cooling means comprising: a rotation axis; a rotator assembly fixed to the rotation axis; a stator assembly surrounds the rotator assembly; a bearing attached to both ends of the rotation axis to support the rotation axis; a hybrid fan formed from combination of the radial fan and the axial-flow fan used as a cooling means placed between each bearing and the rotator assembly to cool the stator assembly and the rotator assembly; an endshield attached to both ends of a housing to protect the structure and consists a plurality of air intakes; and a plurality of through holes formed to the rotator assembly to circulate the air. Wherein, the hybrid fan comprises: a hub having two cylinders with the different radius are connected to the axis direction; an axial-flow fan placed in the outer surface of the cylinder of the hub of a larger radius; and a radial fan placed in the outer surface of the cylinder of the hub with a smaller radius.
From the subsequent detailed description, appended claims and drawings, other objects and advantages of the present invention will become apparent to those skilled in the art.